2 time zones

Also, why does South Dakota have two time zones? The Northern Pacific continued to make the time change between Central and Mountain time at Mandan. Which is pretty much the same boundaries as the current time zone line. And I believe that is the reason Southwestern ND to this day is in the Mountain Time Zone and the rest of the state is in the Central Time Zone.

Thereof, where does the time zone change in South Dakota?

Time Zones in South Dakota South Dakota east part is in the Central Time Zone, and its west part is in the Moutain Time Zone. Cities in Central Standard Time Zone include Brookings, Watertown, Sioux Falls, Vermillion, Huron, Mitchell, Aberdeen, Pierre, Chamberlain, Madison and Mobridge.

Is South Dakota in Central Time Zone?

The Eastern part of South Dakota Counties is in the Central Time Zone in the United States. The Western part of South Dakota Counties is in the Mountain Time Zone in the United States. Mountain Standard Time (MST) is 7 hours behind Greenwich Mean Time (GMT-7).